The present invention relates to the decontamination art. It finds particular application in conjunction with sterilizing or disinfecting medical, dentistry, veterinary, mortuary, and laboratory instruments and equipment and will be described with particular reference thereto. It will be appreciated, however, that the invention is also applicable to a wide variety of technologies in which reagents are mechanically released at the time of use.
Decontamination connotes the removal of hazardous or unwanted materials, such as bacteria, mold spores, other pathogenic life forms, radioactive dust, and the like. Disinfection connotes the absence of pathogenic or harmful life forms. Sterilization connotes the absence of all life forms, whether pathogenic or not. Often, sterilization is measured against the elimination of bacterial endospores which are the living organisms most resistant to conventional sterilants. Microbial decontamination is used herein as the term generic to both sterilization and disinfection.
Heretofore, medical, dental, surgical, veterinary, and laboratory equipment and instruments have often been sterilized in a steam autoclave. Autoclaves kill life forms with a combination of high temperature and pressure. However, steam autoclaves have several drawbacks. The high temperature and pressure vessels tend to be bulky and heavy. The high temperature and pressure tends to curtail the useful life of the endoscopes, rubber and plastic devices, lenses, bearings, and portions of devices made of polymeric materials, and the like. Moreover, the autoclave sterilizing and cool down cycle is sufficiently long that multiple sets of the medical instruments are commonly required.
Instruments which cannot withstand the pressure or temperature of the oven autoclave are often sterilized with ethylene oxide gas, particularly at larger medical facilities or hospitals. However, the ethylene oxide sterilization technique also has several drawbacks. First, the ethylene oxide sterilization cycle is even longer than the steam autoclave cycle. Another drawback is that ethylene oxide sterilization is sufficiently sophisticated that trained technicians are commonly required, making it unsuitable for physician and dental offices and for other smaller medical facilities. Yet another drawback is that some medical equipment can not be sterilized with ethylene oxide gas.
Liquid sterilization systems have also been utilized for equipment which could not withstand the high temperatures of steam sterilization. Commonly, a technician mixes a liquid sterilant composition and manually immerses the items to be sterilized. The high degree of manual labor introduces numerous uncontrolled and unreported variables into the sterilization process. There are quality assurance problems with the weakening of the sterilants due to aging on the shelf, technician error in the mixing of sterilants, technician error in the control of the immersion times, technician error between immersion and the rinsing of residue, technician error in exposure to the ambient atmosphere after the rinsing step, and the like.
Another problem with the prior art liquid system resides in the corrosive nature of the strong oxidants that are commonly used as liquid sterilants. Normally, the sterilized items are rinsed to remove chemical residues. This rinsing also adds a variable that reduces the assurance the item has been disinfected or sterilized. Once rinsed, the item is susceptible to reinfection by airborne microbes.
In U.S. Pat. No. 5,209,909 also of the assignee herein, a reagent system was described which used only powdered reagents. The powdered reagents were stored in separate compartments in a two-compartment cup. The two-compartment cup was cut open with knife blades and the two reagents were dissolved in high pressure water. The dissolved reagents reacted to form a sterilant solution with buffers, corrosion inhibitors, wetting agent, and the like.
The all powdered formulation has some notable advantages over the liquid peracetic acid system. Severe restrictions by airlines effectively limit the shipment of liquid peracetic acid to surface transportation. Because liquid peracetic acid has a limited shelf life over which full potency can be assured, precise timing is required to ship the liquid peracetic acid sterilant systems overseas and have them arrive with a satisfactory remaining shelf life.
The present invention provides a new and improved cutter assembly which is ideal for opening powdered reagent containers.